# How to use FIND function here?

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I need to find the very first corresponding value of the payload when time is 0.0000.

Next,find the corresponding value of payload when time is 1.000.Likewise when time is 2.0000 and time is 3.0000. (pls note that payload column needs to convert to decimal values) [file is attached, herewith]

below is the code i used so far:

clc

clear all

fid=fopen('test.txt');

data=textscan(fid, '%*d%f%*s%*s%*s%*d%s', 40 ...

, 'MultipleDelimsAsOne',true, 'HeaderLines',1);

fclose(fid);

S=hex2dec(data{:,7});

Any suggestions?

##### 2 Comments

per isakson
on 13 Feb 2015

### Accepted Answer

per isakson
on 13 Feb 2015

Edited: per isakson
on 25 Feb 2015

"I need to get 1st and 3rd column as my output."   Is this what you want?

fid=fopen('test.txt');

data=textscan(fid, '%*d%f%*s%*s%*s%*d%s', 40 ...

, 'MultipleDelimsAsOne',true, 'HeaderLines',1);

fclose(fid);

S = hex2dec(data{2});

my_output = cat( 2, data{1}, S );

>> whos my_output

Name Size Bytes Class Attributes

my_output 40x2 640 double

"How to use FIND function here?"   I cannot see how find could be used here.

 

Addendum with inputs from the comments

Add the following lines to the script above.

sbs = floor(my_output(:,1)) + 1;

val = accumarray( sbs, my_output(:,2), [], @mean );

t1 = accumarray( sbs, my_output(:,1), [], @min );

t2 = accumarray( sbs, my_output(:,1), [], @max );

out = [ t1, t2, val ];

fprintf( '%g, %g, %g\n', transpose( out ) )

The script will now output

0, 0.998058, 4.39375e+12

1.09832, 1.99722, 4.39375e+12

2.09746, 2.99636, 4.39375e+12

3.09557, 3.89427, 4.39375e+12

 

A second addendum with inputs from the comments

Replace

val = accumarray( sbs, my_output(:,2), [], @mean );

by

first_value = @(vec) vec(1);

val = accumarray( sbs, my_output(:,2), [], first_value );

to get "very first corresponding value of the payload".

From testing and the documentation I understand that accumarray does not keep the order of the input values.

Correction: "does not keep" should be "does keep". If not, the function, first_value would be useless.

##### 9 Comments

per isakson
on 21 Feb 2015

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